The much better approach would be to find about 5-10 competitors on Twitter and take the intersect of all their followers. Those are people that actually care

The much better approach would be to find about 5-10 competitors on Twitter and take the intersect of all their followers. Those are people that actually care about your market. I saw an app on App Engine out there that did this, and I've considered for a long time trying to make a business out of tools like this to analyze competitor's usage of social media to attempt to find decent leads.